1. Field of the Invention
The present invention pertains to a method for supporting a partial denture and an improved support bracket or rest for the denture frame.
2. Background
In the art of prosthodontics the replacement of missing teeth in the mandibular region of the mouth has presented several longstanding problems. Partial dentures for the lower teeth cannot take advantage of structure other than the remaining teeth themselves or permanent crowns for supporting the denture frame. As compared with the maxillary region there is no bony structure, such as the hard palate, to which the mastication forces can be transferred. Moreover, if the mandibular anterior teeth are the only ones which are sound these teeth do not have sufficient enamel thickness to provide for the formation of a suitable recess or rest seat in which a corresponding portion of the denture frame may be fitted.
Since the transfer of mastication forces and forcible contact of the denture with the gingiva should be avoided, and the mandibular anterior teeth are in many cases the only remaining sound tooth structures available for supporting the denture frame, the prior art practice has been to provide rests where enamel thickness is marginal or placement of rests in positions wherein the forces exerted thereon tend to rotate or deflect the tooth. Alternative techniques have included crowning the mandibular anterior teeth so that permanent rests can be provided, or the anterior teeth are removed so that a full denture plate can be inserted. From an economic and health standpoint none of these techniques is as desirable as the provision of a suitably supported partial denture. For example, in regard to full mandibular dental prostheses they are almost always more difficult to retain than a well made partial denture. Mobility of partial or full dentures tends to accelerate the amount of bone loss which can greatly decrease the time span during which the patient can wear a dental prosthesis successfully. Accordingly, prior to the development of the present invention the provision of partial dentures for the mandibular region has been fraught with several problems, depending on the tooth structures available for supporting the denture frame, and particularly in instances where only the mandibular anterior teeth remain relatively sound as structures for anchoring or supporting a portion of the denture plate.